Critical Phenomena and Exchange Coupling in Magnetic Heterostructures

↓ Direkt till sidans innehåll
↓ Direkt till sidans sekundära innehåll (sidomenyn)

Sökning: L4X0:1651 6214 > Critical Phenomena ...

Critical Phenomena and Exchange Coupling in Magnetic Heterostructures

Ahlberg, Martina, 1980- (författare): Uppsala universitet,Materialfysik

Andersson, Gabriella, docent (preses): Uppsala universitet,Materialfysik

Hjörvarsson, Björgvin, professor (preses): Uppsala universitet,Materialfysik

visa fler...

Bramwell, Steve, professor (opponent): London Centre for Nanotechnology

visa färre...

(creator_code:org_t)

ISBN 9789155482824
Uppsala : Acta Universitatis Upsaliensis, 2012
Engelska 58 s.
Serie: Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 ; 902

Relaterad länk:: https://uu.diva-port... (primary) (Raw object); visa fler...; https://urn.kb.se/re...; visa färre...

Doktorsavhandling (övrigt vetenskapligt/konstnärligt)

Abstract Ämnesord

Stäng

The continuous phase transition in thin magnetic films and superlattices has been studied using the magneto-optical Kerr effect (MOKE) and polarized neutron scattering (PNR). It has been shown that the critical behavior of amorphous thin films belonging to the 2D XY universality class can be described within the same theory as crystalline sample. This means that quenched disorder only serves as a marginal perturbation in systems with this symmetry. The connection between interlayer exchange coupling and the observed critical behavior in Fe/V superlattices was explored. The results prove that the origin of unusually high values of the exponent β can be traced to a position dependence of the magnetization at elevated temperatures. The magnetization of the outermost layers within the superlattice shows a more pronounced decrease at lower temperatures, compared to the inner layers, which in turn have a more abrupt decrease in the vicinity of the critical temperature. This translates to a high exponent, especially when the layers are probed by a technique where more weight is given to the layers close to the surface, e.g.MOKE. The interlayer exchange coupling as a function of spacer thickness and temperature was also studied in its own right. The data was compared to the literature, and a dependence on the thickness of the magnetic layers was concluded. The phase transition in amorphous FeZr/CoZr multilayers, where the magnetization emanates from ferromagnetic proximity effects, was investigated. Even though the determined exponents of the zero-field magnetization, the susceptibility and the critical isotherm did not correspond to any universality class, scaling plots displayed an excellent data collapse. Samples consisting of Fe δ-layers (0.3-1.4 monolayers) embedded in Pd were studied using element-specific resonant x-ray magnetic scattering. The magnetization of the two constituents showed distinctly different temperature dependences.

Ämnesord

NATURVETENSKAP -- Fysik -- Den kondenserade materiens fysik (hsv//swe)
NATURAL SCIENCES -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Nyckelord

phase transitions
critical behavior
2D XY model
MOKE
magnetic thin films and superlattices
amorphous multilayers
magnetic proximity effects
Physics with spec. in Atomic, Molecular and Condensed Matter Physics
Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik

Publikations- och innehållstyp

vet (ämneskategori)
dok (ämneskategori)

Hitta via bibliotek

Critical Phenomena and Exchange Coupling in Magnetic Heterostructures (Sök publikationen i LIBRIS)

Till lärosätets databas

Hitta mer i SwePub

Av författaren/redakt...: Ahlberg, Martina ...; Andersson, Gabri ...; Hjörvarsson, Bjö ...; Bramwell, Steve, ...

Om ämnet

NATURVETENSKAP: NATURVETENSKAP; och Fysik; och Den kondenserade ...

Delar i serien: Digital Comprehe ...

Av lärosätet: Uppsala universitet

Sök utanför SwePub

Sök vidare i:: Google; Google Book Search; Google Scholar

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

LIBRIS.kb.se